Mechanism for registering sheets



June 10, 1952 H. T. BACKHOUSE MECHANISM FOR REGISTERING SHEETS FiledJuly 29, 1947 Patented June 10, 1952 MECHANISM FOR REGISTERING SHEETSHeadley Townsend Backhousc, Wentworth, England Application July 29,1947, Serial No. 764,599 In Great Britain February 23, 1945 Section 1,Public Law 690, August a, 1946 Patent expires February 23, 1965 1 Claim.

This invention comprises improvements in or relating to mechanism forregistering sheets being fed to printing presses and other machines.

The invention relates to sheet registerin mechanism of the type(hereinafter referred to as the type described) comprising a layboard.means such as a tape conveyor for feeding the sheets over the layboard,one or more lays against which the front edge of each sheet in turn isfed to register the position of the sheet before it is taken by theprinting press or other machine, and suction grippers (acting assmoothers) operating above the layboard and arranged to grip the uppersurface of each leading sheet and to move with it up to the front lays.

The purpose of the suction grippers in mechanism of the type describedis to overcome the difficulty, which sometimes arises when such grippersare not employed, particularly when sheets are being conveyed at highspeed, that the leading sheet may arrive for registration at the frontlays a little too early or too late in relation to the timed cycle ofoperations. In the former case the sheet may buckle and spring back fromthe front lays and in the latter case the sheet may be taken by thegrippers or equivalent devices of the printing press or other machinebefore there has been time to effect registration between the front edgeof the sheet and the lays. In both cases inaccuracies in registrationmay result.

According to the present invention suction grippers operating above thelayboard and acting as smoothers are used in conjunction withpreliminary sheet stops which travel with the grippers toward the frontlays.

The invention accordingly consists in sheet registering mechanism of thetype described characterised by preliminary sheet stops operating abovethe layboard and arranged to travel with the suction gripper elementstowards the front laysof the printing press or other machine to effect apreliminary registration of the sheets while they are gripped by thesuction gripper elements.

An example according to the invention will now be described withreference to the accompanying drawings (partly diagrammatic) in which:

Figure 1 is a perspective view (with parts broken away for the sake ofclearness) showing the essential elements of the apparatus, and

Figure 2 is a longitudinal cross-section of a combined suction smootherelement and preliminary sheet stop.

Like reference numerals indicate like parts in both figures.

In this example there are two suction grippers (of which only one isshown in the drawings) spaced apart across a layboard ill at positionsto engage the leading edge H of each sheet l2 as it approaches the frontlays I3 (only one of which is shown in the drawings) which arepositioned at the forward end of the layboard Ill and are operable inusual manner. Each gripper is constituted by a box-like element Hicarried at the end of a forwardly-extending tubular arm 15 located abovethe layboard. Each gripper i4 is provided with a multiple point suctionmouth 16 communicating by an interior conduit H with the bore of thetubular arm 15. Each preliminary sheet stop-one being associated witheach gripper l4-is in the form of an angle-shaped finger l8 carried by aspring blade l9 from the inner end of the suction box l4. Suction isapplied to the tube I5 by a nozzle 20. The arms [5 with their associatedsuction grippers and preliminary sheet stops are adapted to bereciprocated longitudinally and to be elevated and lowered in relationto the layboard by means of any convenient mechanism indicated generallyby the reference numeral 2| in Figure 1, the movement of the arms beingin synchronism with the main cycle of operations of the machine.

The apparatus described above may be operated in the following manner.Suction is applied at the mouths it before the leading sheet has reachedthese mouths. The effect of this is to apply a brake to the travel ofthe sheet so that it does not become crowded up against the preliminarystops [8 but is smoothly arrested by the preliminary stops in a squaredup position. The mechanism 2| then operates to forward the grippers I4,suction being maintained until the front edge of the sheet reaches andis arrested by the front lays 13 of the machine. At this point thesuction is cut off or reduced so that the sheet is left at the frontlays while the stops and grippers slide off the sheet. Thereafter themechanism 2| operates to lift the combined suckers and preliminarystopsleaving the sheet clear to be taken into the press-and to returnthem to their initial position ready to engage the next sheet.

In an alternative method of operating the apparatus, the combinedsuckers and preliminary stops are arranged to be moving towards thepress lays l3 at a lower speed than the sheets are advanced by the mainconveyor. The leading sheet then overtakes the combined suckers andpreliminary stops and is squared up" to these stops while moving to thepress lays.

I claim:

In a sheet feeder a feed board, a sucker arm, a. sucker at the forwardend thereof having a plurality of suction orifices longitudinally spacedapart in the direction of sheet travel over the feed board, meanspivotally connected with the rear end of said arm for moving the suckerback. and forth in the direction of sheet travel and means for raisingthe sucker while a sheet is being withdrawn from the feed board, thesucker being arranged to rest on a sheet on the looard and with suctionapplied to the orifices" during its forward travel and a sheet stoparranged to i travel with the sucker and slightly ahead there -0f in thedirection of sheet travel whereby the forward edge portion of a sheetadmitted be tween the sucker and the board will be gradual- 1y sloweddown by suction asthe forward edge of the sheet successively closes thesuction orifices and by relatively slow forward movement of the suckerand the forward edge will be positively arrested and preciselypositioned relatively to the sucker by engagement with the sheet stop.

HEADLEY TOWNSEND BACKHOUSE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 567,730 Wood Sept. 15, 18961,289,628 Breen et al Dec. 31, 1918 2,328,943 Backhouse Sept. '7, 1843

